Level



G. R. ERICKSON March 15, 1938.-

' I LEVEL Filed Sept. 19, 1935 Swa u INVENTVOR; r'ge B. 970,650

a of the bubble tubes.

Patented Mar. 15, 1938 UNITED STATES PATENT OFFICE 5 Claims.

This invention relates to levels, and more particularly to means forprotecting bubble tubes and glasses of levels of present-dayconstruction.

The objects of the invention are to provide an improved protector; toprovide a protector which will not in any way obscure sight of thebubble when the level is in use; to provide a protector applicable tolevels already in use or upon the market; to provide a protector whichwill not protrude beyond the outermost plane of the level; to provide aprotector which will remain in position where placed; to limit movementof the protector; to provide a simple and readily made as well asinstalled construction; and to obtain other advantages and results asmay be brought out in the following description.

Referring to the accompanying drawing in which like numerals ofreference indicate similar parts throughout the several views,

Figure l is a side elevation of a level embodying my invention;

Figures 2, 3 and 4, are cross sections thereof on lines 22, 33 and 44respectively;

Figure 5 is an edge view of one of the proteco tors; and

Figure 6 is an end view of the protector.

In the specific embodiment of the invention, the reference numeral Idesignates the level body generally, the same being here shown asproviding integral edge rails 2, 2 and; end pieces 3, 3. At intervalsbetween the side rails are provided integral cross connections 4 whichare appropriately socketed to receive bubble tubes 5, and, if desired,protective glasses 6, 6 on opposite sides The foregoing is descriptiveof levels now upon the market, so that I wish it distinctly understoodthat my invention is not only applicable with respect to such levels,but others which may differ in detail from the particular one selectedfor illustration herein. Levels of this type are generally open betweenthe side rails and between the end pieces and cross connections as wellas between cross connections. So far as the present invention isconcerned, these openings may be considered as slots 9 through the levellongitudinal thereof and transverse to the plane of the broad side.Furthermore, the plane of the broad side may be considered as the planedefined by the rim edge surface of the 0 two side rails at the broadside. In other words,

it is the plane of rest if the level were placed upon a flat surfacebroad side down.

In carrying out my invention, I prefer to shoulder off the side railsalong their inner sides, as at I, thereby providing said shoulders ateach broad side of the level in a plane inset from and parallel to theplane of the broad side. The cross connections are likewise inset as faras the shoulders. Longitudinal of the level, on the inside of the siderails, are re-enforcing ribs 8 midway between the planes of the broadsides and parallel thereto.

Further, according to my invention, I provide a slidable protector IDfor each of the socketed cross connections. Description of one,therefore, will sufiice for all. Said protector is shown as comprising apair of parallel, or substantially parallel cover plates I I, I I. Inthe present showing, said cover plates are integral with an endconnection I2 common to both and integral therewith, whereby theprotector will appear U-shape in edge view. The said end connection isnotched, as at I3, I3, at opposite sides to clear the two re-enforcingribs 8. The longitudinal edges of the cover plates are enough wider thanthe end connection l2, as clearly shown in Figures 2 and 6, so that theside margins of said plates will ride upon the shoulders I.

Midway between the side edges of the cover plates and spaced from thefree ends thereof, is a transverse securing means, such as rivet I4, bywhich the plates are held toward each other in contact with theshoulders of the level. Between the plates and carried by the rivet orthe like, is a sleeve or similar member I5 which will act in one of itsfunctions to limit the action of the rivet in drawing the plates towardeach other. In another function, the member I5 acts as a stop to limitsliding of the protector in covering direction by engagement with thecross-connection carrying the bubble tubes being protected. In Figure 1,the lower one of the protectors is shown in protecting position, and themember 15 thereof is shown engaged with the socketed cross-connection.To make use of that bubble tube, the protector would have to he slidlongitudinally in the direction of the arrow to expose the tube. Theother two protectors shown in Figure 1 have already been slid to exposethe leveling instrumentalities, and to return them to protectingposition, they would have to be slid in the directions of the arrowsthereon. It is here to be noted that none of the parts of the protectorsare at any time projecting from the surface plane of the level.Furthermore, the protector, in providing connected cover plates, willsimultaneously expose or uncover the leveling instrumentality at bothsides of the level.

In the construction and assembly of my improved protector with a level,it is preferred that a frictional contact be assured between the sidemargins of the plates and the shoulder of the level rail. This may beaccomplished through resiliency of the metal of the protector and properproportioning of the length of sleeve l5. For instance, the sleeve mayhave a length equal to the distance through the level from shoulder toshoulder, in which event the side plates normally bulge slightly attheir middle part and are drawn fiat by the rivet. However, by havingthe plates initially .flat and the sleeve slightly less thanjthedistance from shoulder to shoulder, the rivet will concave the platesand thereby obtain the desired frictional engagement with the shoulders.The protector will thus be held in any position to which it is slid.Finally I might state that I prefer to employ metal for the protectorplates, and wood for the spacing sleeve, but do not confine myselfthereto. It is desirable, in using metal protector plates, to round thecorners somewhat or otherwise prevent them from cutting into the metalof the level upon sliding the plates.

Obviously detail changes and modifications may be made in theconstruction and use of my invention, especially to accommodatethe sameto. diiferent makes and types of. levels now upon the market.Furthermore, while I have selected ametal level for the specificillustration herein, let it be said that the invention is equallyapplicable, to, wood levels, which, if not already provided withlongitudinal slots, may have slots cut therein for reception of thetransverse connec-, tions between the protector plates, With woodlevels, the end connection between the protector plates would have lesswidth since the slot in the level would be less wide than in a metallevel, and, in fact, in either case, the end connection need not beintegral, but may be an applied connectionsuch as a rivet if so desired.,The invention isaccordingly not to be limited to details shown anddescribed, except as set forth in the following claims,

Having thus described the invention, I claim:

1. A level protector for a levelhaving, a level instrumentality and aslot longitudinal of the level approaching said instrumfintality, said,pro-, tector comprisinga pair of substantially parallel, cover plateshaving sides and ends, and; a plurality of connecting means extendingfrom one plate to the other between the plates for riding,

in the slot of. the level, each of said connecting means being spaced ata distance from one end of the protector thereby providing space betweensaid plates having unobstructed opening at the said end of the protectorfrom which said con necting' means are spaced with one connecting meansengageable with the end of the slot next said level instrumentality andwith the protector projecting over said instrumentality.

2. A level protector comprising a pair of substantially parallelfcoverplatesahaying sides and ends with the dimensions of the sides of greaterlength than the ends and providing side margins next the said sideedges, and a plurality of connecting means between the plates, saidplates having a width greater than each of said connecting means, andsaid connecting means being inset from both side edges of the plates forproviding said margins continuous from end to end of said plates.

3. A level protector comprising a pair of substantially parallel coverplates having sides and ends with the dimensions of the sides of greaterlength than the ends and providing side margins next the said sideedges, and an end connection between said plates, said end connectionhaving less width than said plates and being inset from both side edgesof both plates for providing side margins continuous from end to end ofsaid plates.

4. A level protector for a level having a level instrumentality and aslot longitudinal of the level approaching said instrumentality, saidprotector comprising a pair of substantially parallel cover plates, anend. connection between said plates at one end of the protector, andmeans spaced from the other end of the protector for establishingconnection between the plates intermediate the endscthereof, therebyenabling said plates to project over and. protect the levelinginstrumentality against which said: connecting means is brought intocontact in use.

5. In combination with a level having a level instrumentality to beprotected, and having a slot directed longitudinally toward saidinstrumentality, of" a protector slidablelongitudinally of said slot to,cover and. uncover said instrumentality, said; protector havingconnecting. means extending transversely throughsaid slot.

GEORGE R. ERICKSON.

